Sensorimotor learning plays a critical role in the acquisition and refining of all skilled movements, including speech production. From early babbling to fully mature speech articulation, the central nervous system acquires and updates neural representations of the intricate motor-to-auditory transformations that take place from the generation of motor commands to vocal tract movements and speech sound output. Moreover, auditory-motor learning - the process through which such neural representations are learned and maintained - is believed to play an important role in the etiology of developmental speech disorders such as stuttering and childhood apraxia of speech. This series of six integrated experiments therefore seeks to gain a better understanding of the principles and mechanisms involved in speech sensorimotor learning in general and in auditory-motor learning in particular. The overall program of research is designed around the dual short-term goals of (a) optimizing the rate and extent of auditory-motor adaptation, and (b) minimizing the rate and extent of de-adaptation (decay of sensorimotor learning). The findings from these studies will also elucidate the developmental progression of auditory-motor learning during childhood as well as differences in auditory-motor learning between children and adults. Furthermore, given that the core experimental paradigm for auditory-motor adaptation studies causes speakers to automatically alter their speech output in a short period of time, without instruction, and without effort, one long-term goal of the proposed research program is to develop novel, computer-assisted clinical procedures that induce adaptive changes in speech motor behavior by systematically altering the speaker's auditory feedback. Thus, this work's direct relevance to public health lies in the fact that the generated knowledge will contribute directly to an in-depth understanding of typical speech development, the maintenance of speech articulation skills throughout the lifespan, and fundamental sensorimotor mechanisms underlying developmental speech disorders, while simultaneously paving the way for highly innovative clinical techniques for the treatment of a wide variety of speech disorders.